Good questions, but if you're thinking of starting a new tournament circuit don't quit you're day job. Using All-Star Bass Team just as an example, the stated pay back is 80% on entry fee ($135) and Big Fish ($35) so they keep 20%. For 100 teams thats $2700 they keep from the entry fees and depending on the number of teams that get into the big fish option (say half or 50 teams) they keep another $350. So the minimum they get is $3050 in this case. Then they have Mini-Ts, Maxi-Ts, Senior-Ts, Magnum-Ts where I think they payback 10 entry fees for every 11 that sign up. That's easily another $500 they keep. So roughly $3500 per tournament for All Star with 100 teams before expenses. (I'm assuming they define 80% payback as 80% of the team and big fish entry fees collected not 80% of what's left after expenses are paid. Ask the tournament organizer how they calculate the 80% payback.)
A true 100% payback means the organizer is losing money, unless expenses are being covered by sponsors
Also tourny's have lots of things to pay for. Insurance, permits(which is a %) equipment used for the tourny, The food. gas etc. not te mention they also have to pay more for parking I believe due to the amount of space they take.
and coffee & donuts in the am. Plus they pay the help sometimes as well.